1. Field of the Invention
The present invention relates to a glossy ink jet recording medium having the feel of glossy coated paper for use in offset printing and to an ink jet recording method conducted using the ink jet recording medium.
2. Description of the Related Art
The Ink jet recording system makes full color printing easily achievable and is quiet. Therefore, the ink jet recording system is being used in many applications as printing performance rapidly improves. The applications include, for example, document recording using document preparation software, digital image recordings such as digital photographs, copies of scanned silver halide photographs and beautiful printed materials such as books, and image producing for display such as limited edition posters. In recent years, the ink jet recording system has been used frequently in place of the offset printing mode, particularly for the commercial printing industry that is involved in printing small lots of many different productions.
Ink jet recording media with compositions suited for individual applications have been proposed. For example, a non-coated paper type medium is used when only letters are printed directly on the paper surface. A coated paper type medium on which an ink receiving layer has been formed as a coating layer is used when qualities of resolution and color reproducibility rivaling those of silver halide photographs are desired since the ink emitted by a printer needs to be absorbed. When a particularly high gloss is required for coated paper media, casting methods are used to prepare cast paper type media and the like. At the same time, a roll type medium containing a thick coating layer was developed and is being used in posters and display applications.
However, glossy ink jet recording paper that can replace glossy offset printing paper is almost non-existent due to very high production costs. Since the amount of the ink usage increases as color reproducibility of the image is improved in a coated paper type medium, the higher ink absorption capacity in ink receiving layers is desired. Therefore, substances such as synthetic amorphous silica and the like are frequently used in ink receiving layers. The ink absorption improves in these cases, but there are problems that the gloss declines and the texture diverges from those of offset printed materials. Furthermore, a feel is different from that of an offset printed material in the case of a cast paper type medium since the medium is much more glossy in comparison to conventionally coated offset printing paper and the paper is thicker. In addition, the production cost for such ink jet recording media is more expensive than that of conventionally coated offset printing paper since expensive raw materials such as silica, alumina, poly(vinyl alcohol), ethylene vinyl acetate emulsions and ink fixing agents (polyamine type, DADMAC type and polyamidine type agents) are used in large amounts.
When a conventionally coated offset printing paper is printed using an ink jet printer, poor image qualities such as feathering (blurring), bleeding (blurred outlines), uneven printing (poor uniformity) of solid image (poor image density) and cockle (undulation of printed areas) are rose due to the low ink absorption capacity of the coated layer.
Coated paper for gravure printing is one type of printing paper that, among coated printing papers, has relatively high oil absorbance and is slightly better for printing using an ink jet printer than is conventionally coated offset printing paper. However, poor image qualities similar to those described above for conventional offset printing paper appear in a coated gravure printing paper since the paper is calendered using a high nip pressure to achieve gravure printing adaptability which results in a coating layer that contains very few voids, and the ink absorption capacity is inadequate.
Given this situations, a medium composed of a recording layer (coating layer) containing kaolin with an average particle size of from 0.2 μm to 2.0 μm satisfying 1≦L/W≦50 [where L is the long diameter of a particle and W represents the short diameter (thickness) of the particle] and a 75° gloss for the recording layer surface according to JIS-Z-8741 of at least 40% is disclosed as an ink jet recording medium with the feel of a coated offset printing paper. (For example, see Patent Reference 1).
In addition, a constitution containing a pigment coated layer (coating layer) having kaolin as the main ingredient and having a designated cobb sizing (degree of water absorption) after the pigment coating layer is impregnated with a cationic resin is disclosed as an offset printing paper with ink jet adaptability. (For example, see Patent Reference 2.)
Furthermore, a recording sheet (see Patent Reference 3) with an ink receiving layer containing columnar, needle-shaped orthorhombic aragonite calcium carbonate as a pigment and containing as a binder an epoxy resin and a styrene butadiene type copolymer resin on the film base support medium is disclosed as an ink jet recording paper containing SBR (styrene butadiene copolymer) in the ink receiving layer binder. A recording medium (Patent Reference 4) containing in the binder component of the ink receiving layer 5 weight % to 55 weight % of styrene butadiene latex of which 20 weight % to 45 weight % is derived from butadiene monomer is also disclosed. A recording paper (Patent Reference 5) containing clay and calcium carbonate with a specific oil absorption amount as the pigment in the ink receiving layer in addition to containing as the binder an acrylamide/diallylamine type polymer and a styrene butadiene type copolymer is disclosed.
[Patent Reference 1] Japanese Patent Application Publication No. 2004-209965
[Patent Reference 2] Japanese Patent Application Publication No. 2004-270104
[Patent Reference 3] Japanese Patent Application Publication No. H04-250092
[Patent Reference 4] Japanese Patent Application Publication No. H09-11613
[Patent Reference 5] Japanese Patent Application Publication No. 2004-82464